zxer

I have read all about the thin head gaskets, is there any problem shaving the head and using a stock gasket?

ZXER

SHADY280

i have 10.8:1 cr and the stock hg was fine, i upgraded to a multilayer steel just for insurance after thousands of kms of abuse.

NismoPick

Hey buddy! Welcome to ZDriver!

No prob w/ shaving the head as long as you don't shave a ton off. I think after something like .040 or .050 you are supposed to use cam tower shims.

Machine off .020 and use a 1mm MLS head gasket... that will up the CR a bit. To get technical, plug in all your variables here: http://www.ozdat.com/ozdatonline/enginedesign/

SHADY280

decking the head all depends on the casting number as well. you can even change the combo up and eliminate all the machine work. theres tons of info, but it all depends on what you wanna do and what you have at your finger tips. if you have a p79 id shave it .080" and shim it the same. the results are amazing

FubarI33t

Of course we all know flattops with a dished style head like N42 and the P90 twins are a quick way to up compression. Of course the combustion chamber of a P90 series is more disierable then a N42. Just watch how much you go up. Our engines are more suspectable to ping then other engines. But proper tuning can help you get the high C/R's.

BlueKitsune

You could always paint your pistons!

j/k dont, if you do I will laugh and at the same time feel bad for how stupid you are. then I'll just laugh at you more lol

P90 shaved .080 with flattops is a good combo without running the risk of ping to high. Sense it quenches the mix into the spark plug and the P90 for better flow

WildmaN

So.....if I needed to have my head shaved. Because it would be warped. When I get around to taking it off. Anyway would shaving it .020, and using the MLS head gasket be okay. On a stock '82 n/a engine? If so, I might have that done, when I do take the head in. Also how much extra would that cost. To shave it to those specifications?

NismoPick

If you're just rebuilding a stock n/a motor w/ no other hp mods... I wouldn't spend the money on a MLS head gasket ($150-$200). A stock Felpro will work fine ($20).

It's when you have a high CR or boosting, that the MLS head gasket provides the extra needed protection.

SHADY280

mls isnt worth it i agree. i abused my high cr engine with the good ol' felpro with no probs. kinda a waste of money if your not going over 11:1 or boosting imo. wildman deck some more off, youll be happy, even .010" more to .030 will really be noticed.

aojedam

i went to a local machine shop here in so cal and they quoted me 350 to shave and shim the head to 80 thousanths. including a valve job and the whole head check/replacement of necessary components

Kerias

so im new here to the Z community and i was wondering i read the thread and stuff but im still alittle confused... i would love to bump the compression on my l28 but i cant seem to find the valve clearances or how high of a compression i can make it with out blowing everything to pieces... from what i understand i have a 1982 280zx non turbo 5 speed it runs stock with 8.8:1 CR??? you guys were talking about vin numbers to tell what pistons it has how do i tell?<...new to vin identifying. this is my first sports car so id like crash corse please lol <nOOb thanks

SHADY280

wow dig up an old thread. whats your casting numbers, thats what we were refering to. use our stickies if you cant find them.

Kerias

here is my casting numbers... is there any way to increase compression with out spending a **** ton of money? if i can skip shaving (unless its easy)... New head? domed pistons that aren't $200 a piston?

FricFrac

Fill the combustion chamber with lead?